This invention relates to a method of and an apparatus for adjusting the delivery quantity of multicylinder fuel injection pumps of the type having a drive unit and a clamping device. The present invention relates, more particularly, to such an apparatus for adjusting the delivery quantity of multi-cylinder fuel injection pumps having pistons, with at least one inclined control edge, which are axially and rotatably guided in cylinder barrels and are each held in their fitting positions at least indirectly by a securing flange clamped against the upper front face of the pump housing by screws. The pistons of the in-line pump are rotatable within a defined angular region to adjust the delivery quantity and are constructed to receive a pressure valve in an extension of the bore guiding the respective pistons. The invention further is concerned with a delivery quantity measuring apparatus for measuring and indicating the quantity of fuel delivered for a given number of piston strokes or unit of time.
Multi-cylinder fuel injection pumps in the form of in-line pumps, more particularly pumps for injecting fuel in diesel engines are mass produced and thus, in addition to reliability of operation, it must be possible for these pumps to be produced, tested and adjusted in an economical manner.
It has been found that the manufacturing of injection pumps can be very highly mechanized, even to the extent of introducing production, transfer and assembly lines. However, using known testing and adjusting methods, the testing and adjusting of the individual elements of the pumps and the functions thereof to effect a uniform delivery quantity have always been very time consuming and require a large staff. Consequently, the conventional testing and adjusting methods are accordingly extremely expensive. In the known testing and adjustment methods, the injection pumps are placed individually on test benches, are connected up and are adjusted in the course of a number of operations by measuring the delivery quantity of the individual elements. These prior methods also involve manually correcting the position of rotation of the cylinder barrels equipped with control bores relative to the pistons having the inclined control edges. Apart from the adjustment method in which the cylinder barrels are rotated within a defined angular region to adjust the delivery quantity and which is used with the fuel injection pumps described initially, other adjustment methods are also known for use with injection pumps of similar construction. For example, methods are known wherein the connection between the adjusting rod and the piston is adjusted. A disadvantage in all the known testing and adjusting methods is that the adjustment of the pump depends in considerable extent on the skill of the mechanic, that is, it is subjectively influenced. In addition, the adjustment method can only be carried out with stationary, that is non-driven, pumps, an extremely time consuming process. Thus, when injection pumps are being mass-produced, for example, on a production line and assembly line, each production line or assembly line must include a large number of test benches with a corresponding number of mechanics.